The present invention relates to arch or foot supports for insertion in footwear in order to provide better comfort and more correct positioning and support of the wearer""s feet, and to a method of manufacturing such supports.
Many individuals who are on their feet or walking for significant periods of time encounter problems usually associated with uncomfortable footwear. Such problems often arise as a result of insufficient arch support in conventional shoes and other footwear. Thus, various types of shoe inserts have been devised in order to alleviate such problems. Some inserts consist only of a foam or padded cushion member or insole, and provide no arch support. It is also known to provide more sophisticated arch supports formed of molded rigid or semirigid materials, such as plastic, and these are sometimes custom-fitted to the individual, which makes them relatively expensive. In some cases, a leather upper layer is applied to the top surface of the arch support.
The molded plastic material typically used for arch supports has a relatively smooth surface and sometimes tends to slip relative to the shoe, or the user""s foot may slip on the smooth upper surface of the device. This can cause misalignment and discomfort. In some prior art molded inserts, it is known to provide raised ribs or other uniform raised patterns on the lower surface of the arch support. However, this increases manufacturing expense and may potentially damage the sole of the shoe. In U.S. Pat. No. 4.694,590 of Greenawalt, an arch support for a heeled shoe has a patch of hook and loop type fastener material at the heel, which engages a mating pad of hook and loop fastener material secured in the heel region of the shoe. This requires modification of the shoe itself and results in a shoe which cannot be worn without the insert.
It is an object of the present invention to provide a new and improved arch support device.
According to one aspect of the present invention, an arch support device is provided, which comprises a substantially rigid member having a periphery shaped to conform to at least part of the periphery of a wearer""s shoe, the member having an upper surface, a lower surface, and being contoured to follow the contours of the sole of a wearer""s foot, the member having a heel region at one end, an arch region, and a toe region at an opposite end, each region being designed to lie under the corresponding regions of a wearer""s foot when in use, at least the heel region of the lower surface having a non-smooth surface portion for resisting slipping of the element relative to the sole of a shoe in which it is inserted, the non-slip surface portion having a surface roughness of not more than 0.02 inches.
The non-slip surface portion is a molded surface texture in an exemplary embodiment of the invention, produced by a sand-blast texture finish of a corresponding portion of a mold in which the device is formed by injection molding. The mold finish may have a relatively even surface roughness in the range of around 0.001 to 0.01 inches peak to valley, and, in an exemplary embodiment, the mold surface roughness was in the range from 0.001 to 0.002 inches. The measurement is of the average peak to valley depth or height of the random depressions in the mold surface formed by the sand-blasting. This finish produces a dull or frosted surface appearance in the molded plastic product, rather than easily visible projections, but the product will still have substantially improved non-slip frictional properties, without tending to damage any surface against which it is placed. It will also be less expensive than a molding technique to produce a pronounced regular pattern of projections, such as ribs or the like. Vapor-honing may be used for small area sand blasting of predetermined portions of the mold surface.
In an exemplary embodiment of the invention, the lower surface of the arch support element also has a similarly textured non-slip surface portion in the toe region adjacent the front end. Non-slip surface portions may also be provided on the upper surface, to resist slipping between the arch support and the user""s foot. The non-slip portions may be provided only in the heel and toe regions, or may extend over the entire surface of the arch support element, and may be provided on only the lower surface, or on both the lower and upper surfaces.
The non-slip surface portion or portions comprises a surface texturing or roughening formed by sand-blasting or the like, of the type generally known as a xe2x80x9cfrostedxe2x80x9d surface texture. The frosted texture may also be provided by sand-blasting the mold surfaces corresponding to the upper and lower surface of the arch support device, either over part or all of each surface, as discussed above, with the mold surfaces having a sand-blast surface texture over some or all of their area. This produces a frosted appearance and texture to the arch support surfaces, and has very good non-slip properties.
In another embodiment of the invention, an insert of rubber or other slip-resistant material may be provided at the desired locations on the lower and/or upper surface. The rubber insert may be secured by adhesive in a suitable indent in the surface. Alternatively, a rubber layer of appropriate shape and size may be applied on top of the surface of the arch support element at the desired location or locations.
By providing textured non-slip surface portions at regions of the lower surface of the arch support device which contact the sole of the shoe, and regions of the upper surface which contact the sole of the wearer""s foot, the tendency of the arch support to slip relative to the shoe and of the wearer""s foot to slip relative to the arch support can be reduced or eliminated. This provides better positioning accuracy and comfort to the wearer.